Mine prop



Aug. 11, 31931, N. D. LEVIN 1,813,633

- MINE PROP Filed Aug. 27, 1926 I f 24 j W/ 7' Alla-re:

Patented Aug. 11, 1931 UNITED STATES PATENT OFFICE? I COMPANY, or coLuMBus, OHIO, A CORPORATION or OHIO,

MINE mo:-

Application filed August 2?,"1926. Serial No. 131,948.

The present invention relates to certain new and useful improvements in mine props, and particularly to that class of mine props which are adapted to temporari y support a mine roof adjacent a working face, and L to be readily reclaimed after the necessity for such support has passed.

In the longwall system of mining, coal is extracted from itsnative bed from relam tively longfaces which retreat as the mining operation progresses. For the protection of the miners and the mining apparatus, during the mining operations,.means must be provided to support the mine roof im- 1 mediately in front of said coal face, and

economy dictates that these supports shall be reclaimed as the mining operations progress. I am aware that temporary roof supports of various sorts have beenheretofore t proposed which may be withdrawn and again used as the working face recedes. All of suchdevices which have been heretofore proposed, with which I am familiar, are objectionable becauseof their excessive first 4 5 cost, and of the time and labor required for their manipulation.

It is the especial object. of this invention to provide a roof supporting prop which shall be of relatively small initial cost, easy s to place, efiicient in service, and which may be conveniently and expediently reclaimed and relocated as the working face advances.

The means whereby I attain this object is fully set forth in the following specification,

5 and illustrated in the accompanying draw- ,ings of which Fig. 1 is a side elevation, partly in section, of the preferred embodiment of my invention.

40 Fig. 2 is a fragmentary sectional view taken along the line IIII of Fig. 1. i

Fig. 3 is a transverse sectional View taken along the line III-III of Fig. 1-.

Fig. 4 is a diagrammatic elevation, on a 45 reduced scale, illustrating the relation of my improved mine post to the floor and roof of the mine, when said post isin roof supporting position. I

Fig. 5 is a diagrammatic view, similar 60 to Fig. 4, illustrating the method of releasthe ends of the post.

lower end of the casing 2, and abutting; against the fiat end of the post 1, is a cast As shown in the drawings, my improved 4 mine prop comprises a Wooden st 1.,of suitable length which is encased 1n a steel NILS 1). LEVIN, or coLuMBUsoHIo, Assieivon To THE JEFFREY MAN'UFAcTuRiive tubing 2 projecting at both .ends beyond Extending into 1 the steel foot 3 which is held in operative relat1on with the post 1 and easing 2 by a lag screw 4 inserted through 'anaxial aperture 5 in the foot casting 3. A cast steel head 6 projects into the casing 2, abuts against the opposite end of the post 1, and is held in operative relation with the post andcasing by a lag screw 7 inserted through an axial aperture 8formed-in the head casting. At its lower end the foot casting53 is of hemispherical shape adapted to tiltably engage a correspondingly shaped socket 9 formed inga cast steel pedestal 10 which is adapted; to

rest upon the floor of the mine. Thepedestal casting 10 is preferably formed with a relatively broad floor engagin flange 11 adapted to support the weight 0' the postsv andits load without exerting undue pressureupon the mine floor. F ormed-in the body of the pedestal 10 are suitable apertures 12 adapted to receive a hook 13 formed on the 'end' of a rod 14 tov afford a handle for sliding the pedestal 10 along the mine floor into the desired position. At its upperend the head casting 6 18 of rect'angular'cross section, and

the upper edges 15 of its lateral walls 16 present inclined bearing surfaces adapted'to lengagethe corres ondingly inclined ed es a cap castinglS WhlCh':

of the walls 17 o constitutes theroof engaging element of the prop. The cap casting 18 is provided with depending flanges 19 at each side adapted to engage the sides ofthe head casting 6 to prevent lateral displacement of these parts relative to each other. Mounted in suitable apertures of the sidewalls 17 ,of the cap casting 18 is a bolt 20 upon which is pivotally mounted a latch 21. adapted to extend into a slot 22 ofthe head casting 6. The latch 21 is provided with a laterally expanded head 23 adapted to engage the faces 24 of the head casting, to prevent the cap 18 from sliding downwardly upon the inclined surface of the head casting 6.

In the practice, of longwall mining a series of roof supporting props is arranged at suitably spaced intervals in a row extending su stantia ly parallel. w th t e. o fa t sugport'the mlne roof above the area wherein the mining operations are conducted. At each advance of the working face a new. line of props is established, and those of the preceding line are removed to, allow subsidence of the unsupported roof.

To position my improved roof supporting prop in such a system, the pedestal casting 10 is moved over the mine floor. to the desired position. The post 1 is then placed perpendicularly with. its foot resting in the socket 9 and the inclined bearing surface 15 sloping downwardly away from the coal face 25. The cap casting 18 is then placed in position uponthe head of the post and Locked in place by engagement of the latch Wedges 26, or other suitable filling devices, may then be placed between the flange 18 of the cap, and the mine roof 27, as shown inFig. 4:,to hold the post in upright position until. partial subsidence of the roof shallplace a loadfupon it.

a To remove-the prop, an upward blow with a miners pick,,or'other suitable tool, is sufficient to release the latch 21 and allow the head 6 of the post to slide beneath the cap 18, causing thepost to tip towards the coal face 25 and allowing the'cap to. falllto the mine floor. The hook 13. may then be inserted in the aperture 12 and: the pedestal dragged over the mine floor to its new position. The post 1 will. then be restored to its perpendicular position and. the cap 18 readjiisted: and secured. in'place in. the manner above described.

In the devices above describedI have provided a roof supporting prop of relatively small initialicost, whichmay be easily placed in: roof, supporting. position, which is efficient in service, and which may bereleased from one roof. supporting position and. adjustedin another sd quickly that. the danger attendant upon its manipulation is greatly reduced, thereby contributingto increase the safety of the men and apparatusemployed in the mine.

Consideringthe broadaspects of my invention, it will be seen that I have provided a 'propadaptedv to be retained in operative position by longitudinally acting compressive forces, andireleasing means are provided whereby a relativev tipping movement of the upper portion 23--6- to the base pedestal 10is permitted. to render. the prop inoperative. Considering merely portion 2.-3-6 and the cap, itwill be seen that upon releasblethat the section of this bearing portion bB e fG late in the plane of potential tipping of the column. It is, however, desirable in the efficient operation of the device that this bearing portion be either spherical or arcuate in the manner described in order to permit the ready disengagement of the inclined cooperating faces without making their angle of inclination too oblique relative to the horizontal.

It is to be understood that I do not limit myself to the precise construction here shown, as the parts may be subject to wide variation without departure from the spirit of my invention.

hat I claim is:

1. In a prop for supporting a mine roof, the combination: with a pedestal adapted to rest upon the. floor of a mine, of a post havinga substantially hemispherical foot adapted to rocking engagement with a corre.- spondingly formed socket in said pedestal, an inclined bearing, surface formed upon the upper end .ofsaid post, and of roof; supporting cap supported upon said bearingsurface as and for. the purpose set forth.

2. In a prop for supporting a mine roof,

the combination with a'pedestal adapted; to-

rest upon the floor of amine, of-a post having a substantially hemispherical foot adapted. to rocking, engagement with a correspondlngly formed, socket in said pedestal,

an inclined bearing surface formed, on thello upper end-0f Said post, a roof supporting cap. supported; upon said bearing surface, and means preventing, accidental relative movement of said. post and. cap, as and for the purpose set forth.

3. In a prop for supporting a mine roof, the combination with a pedestal adapted to rest upon the floor of a mine, of a post having a substantially hemispherical foot adapted to, rocking engagement with a correspondingly formed. socket in said pedestal, an inclined bearing surface formed on the upper end of said post, a roof supporting cap. supported upon said. surface, and latch means carried by the cap and engaging the post for preventing relative movement of aid p nd. an

4. In a prop for supporting a mine roof, the combinationwith a pedestal adapted to rest uponthefloor of a Inine,a post having a substantially hemispherical foot adapted to rocking engagement with a correspondingly formed socket in said pedestal, an inclined bearing surface formed on the upper end of said post, a roof supporting cap supported upon said bearing surface, and a latch adapted to prevent the sliding of said post relative to said cap, as and for the purpose set forth.

5. In a prop for supporting a mine roof, an upper longitudinally yieldable portion having a lower bearing extremity of armate contour, a base portion having aseat for said bearing extremity and thereby supporting said upper portion in upright position under working conditions, and latch means to retain said upper portion in upright unyielding position and being releasable to relieve load pressure upon said prop and to permit said upper portion to yield'and to rock along the arcuate contour of its hearing extremity for rendering the prop inoperative.

6. In a prop of the class described, the combination with a post having an inclined bearing surface and a shoulder, of a roof supporting cap supported upon said bearing surface, and a latch pivoted to said cap and i releasably engageable with said shoulder to retain said post in supporting relation to said cap.

7. In a prop of theclass described the combination with a post having an inclined bearing surface and a pair of spaced upstanding lugs, of a roof supporting cap supported upon said bearing surface, and latch means carried by said cap and releasably engageable between said lugs for the purpose set forth.

8. In a prop of the class described, the combination with a post having a pair of spaced upstanding inclined bearing flanges, a roof supporting cap having a pair of spaced depending flanges slidably supported upon said post flanges, means for preventing movement of said cap transversely of said post flanges, and releasable means to hold said post in roof supporting relation with sai cap.

9. In a prop of the class described, the combination with a post having a pair of spaced upstanding inclined bearing flanges and a pair of spaced upstanding blocks, of a roof supporting cap having depending flanges slidably supported upon said post flanges, and a latch pivotally mountedwithin said cap and releasably engageable between said blocks.

10. In a mine prop, the combination with a post having an inclined bearing surface; of a roof supporting cap supported upon said surface, and a latch pivotedto oneof said elements and releasably engageable with the other to prevent accidental movement of said cap relative to said inclined surface.

In hand.

y NILS D. LEVIN. 

